1. Technical Field
The present invention relates to a mobile collaborative robot which operates in cooperation with a human.
2. Description of Related Art
In a mobile collaborative robot in which the robot is mounted on a carriage so as to be movable, there is a possibility that a human makes contact with the robot or the carriage, and accordingly, it is necessary to enhance the safety upon contact. Regarding contact with a robot, in conventional devices, a force sensor is provided on the base of the robot to detect the contact of the robot with the external environment (e.g., Japanese Unexamined Patent Publication No. 2011-110630). However, the robot disclosed in Japanese Unexamined Patent Publication No. 2011-110630 is not a mobile robot, and accordingly, contact between a human and a carriage is not taken into consideration.
A self-travelling robot is known wherein a shock sensor is provided on a peripheral surface of a main body of the robot, so that contact of the robot with an obstacle can be detected by the shock sensor (e.g., Japanese Unexamined Patent Publication No. 2007-54942).
However, in order to precisely detect the contact of the self-travelling robot with an obstacle by the shock sensor, it is necessary to provide a large number of shock sensors, thus resulting in not only an increase of the manufacturing cost but also troublesome operations required to determine the optimal mounting positions and postures of the shock sensors. In particular, in an industrial robot, such as a perpendicular articulated robot, when the robot operates, the posture of the robot changes in various ways, and accordingly, when the industrial robot is a self-travelling-type robot, it is difficult to precisely detect contact thereof with an obstacle by the shock sensors.